Central vision

Peripheral vision

This is the less detailed vision we use to see everything around the edges. Glaucoma affects peripheral vision first. Strokes can affect one side of the peripheral vision.

Contrast sensitivity

This is the ability to distinguish between objects of similar tones like milk in a white cup or to distinguish facial features. All eye problems can decrease contrast sensitivity.

Depth perception

This is the ability to judge the position of objects. New vision loss in one eye can affect depth perception, such as the height of a step.

Visual processing

The lens in our eye focuses light rays onto our retina. The retina converts these light rays into signals that are sent through the optic nerve to our brain, where they are interpreted as the images we see. A problem with any of these processes affects our vision in various ways.

The phantom visions of Charles Bonnet syndrome

About 20% – 30% of people with vision loss see lifelike images they know are not real. This is called Charles Bonnet syndrome (CBS). This syndrome is not a loss of mental capacity, but just part of vision loss for some. It is helpful to think of these images as the brain's attempt to replace missing images from the damaged eye.